1. Field of the Invention
The invention relates to a superconductive electric cable in which concentrically arranged superconductive phase conductors, in particular three concentrically arranged superconductive phase conductors, are arranged in a cryostat with an electric insulation arranged between the phase conductors. The phase conductors and the insulations arranged between the phase conductors are arranged around a cooling duct which preferably has a ring-shaped cross section. The cryostat of the above described cable has two concentrically arranged casings. The undulated pipes are preferably of metal, particularly high-grade steel, with spacers and/or insulations being arranged between the undulated pipes, wherein the intermediate space between the casings is evacuated. The concentrically arranged phase conductors are placed within the cryostat and are in contact with cooling medium, particularly liquid nitrogen.
2. Description of the Related Art
WO 2004/013868 describes a superconductive cable with three coaxial phase conductors between which an insulating layer each is arranged. The outer phase conductor is surrounded by a further insulating layer on which a screening of copper is placed. This cable core is arranged in a cryostat including its circumferential screening.